The present invention relates to novel acrylate monomers comprising several quaternary amino groups in the alcohol part, to their process of manufacture and to the novel (co)polymers obtained from these novel monomers.
Compounds of the type of those of formula: 
in which:
R(0) represents H or CH3;
A represents xe2x80x94Oxe2x80x94or xe2x80x94NHxe2x80x94;
D represents a linear or branched C1-C6 alkylene chain;
R(1) and R(2) which are identical or different, each independently represent H or C1-5 alkyl;
are well known in the literature.
Important compounds of this family are N,N-dimethylaminoethyl acrylate (ADAME) and N,N-dimethylaminoethyl methacrylate (MADAME): 
with R(0)=H or CH3.
A very extensive patent literature discloses the manufacture of aqueous solutions of quaternary ammonium salts from ADAME and MADAME, it being possible for these salts, for the most representative among them, to be represented by the formula: 
with R(0)xe2x95x90H or CH3 and R(3) xe2x95x90CH3 or benzyl, it being possible for these salts to be denoted by the abbreviation (M)ADAMQUAT MC or (M)ADAMQUAT BZ, according to whether R(3) represents CH3 or benzyl.
This reaction is a quaternization, in the presence of water, of the starting compound with a quaternizing agent R(3)xe2x80x94Cl.
The aqueous solutions of quaternary salts thus obtained are used in particular to prepare polymers intended to act as cationic flocculents in water treatment.
Patent CZ-A-250 962 has disclosed compounds of formula: 
in which:
R(0) represents H or xe2x80x94CH3;
R(2) represents xe2x80x94CH3, xe2x80x94C2H5, xe2x80x94C3H7 or xe2x80x94C4H9;
R(3) represents xe2x80x94CH3, xe2x80x94C2H5, xe2x80x94C3H7, xe2x80x94C4H9, xe2x80x94C6H5 or
xe2x80x94CH2C6H5; and
Xxe2x88x92 represents Clxe2x88x92 or Brxe2x88x92.
French Patent Application No. 00/00834 of Jan. 24, 2000 has also disclosed compounds of formula: 
in which:
R(0) represents H or xe2x80x94CH3;
R(2) represents xe2x80x94CH3, xe2x80x94C2H5, xe2x80x94C3H7 or xe2x80x94C4H9; and
the compound optionally being quaternized on one of the nitrogens; when the compound is quaternized on only one nitrogen, R(3) and Xxe2x88x92 have the following meanings: R(3) represents xe2x80x94CH3 or xe2x80x94CH2C6H5 and Xxe2x88x92 represents Clxe2x88x92 or CH3OSO3xe2x88x92 or R(3) represents a C1-Cl12 alkyl group and Xxe2x88x92 represents Brxe2x88x92 or Ixe2x88x92; when the compound is quaternized on both nitrogens, the two Xxe2x88x92 groups can be identical or different and the two R(3) groups can be identical, in which case R(3) represents a C5-C12 alkyl group and Xxe2x88x92 represents CH3OSO3xe2x88x92, Brxe2x88x92 or Ixe2x88x92, or different, in which case one of the R(3) groups represents xe2x80x94CH3 or xe2x80x94CH2C6H5 and Xxe2x88x92 represents Clxe2x88x92 or CH3OSO3xe2x88x92 and the other represents a C5-C12 alkyl group and Xxe2x88x92 represents Brxe2x88x92 or Ixe2x88x92.
These known monomers all make possible access to useful flocculents but with a cationicity which is regarded as still inadequate for some applications.
The Applicant Company has now discovered novel monomers which meet this expectation. These monomers thus form the subject-matter of the present invention, as do their process of manufacture and the homo- or copolymers comprising units derived from these novel monomers.
A subject-matter of the present invention is thus first a compound of formula (Ia) or (Ib): 
in which:
R1 represents hydrogen or methyl; and
R2 represents ethyl or isopropyl.
The compounds of the invention can advantageously be provided in aqueous solution, having a concentration of compound (Ia) or (Ib) which is in particular from 60 to 80% by weight.
Another subject-matter of the present invention is a process for the manufacture of the compound of formula (Ia) or (Ib) as defined above, characterized in that:
in a first stage, p-xylylene dichloride: 
xe2x80x83is reacted with a compound of formula (II): 
xe2x80x83in which R2 is as defined above,
xe2x80x83to produce a compound of formula (III): 
in a second stage, the compound of formula (III) thus obtained is reacted with a compound of formula (IVa) or (IVb): 
xe2x80x83in which R1 is as defined above,
xe2x80x83resulting in an aqueous solution of the compound (Ia) or (Ib) respectively, the water of which is removed, if appropriate.
In the first stage, the reaction is generally carried out in a solvent medium, such as tetrahydrofuran, with a molar ratio of the p-xylylene dichloride to the compound (II) of 0.8 to 1.2, preferably 0.9 to 1.1, at a temperature of 5 to 60xc2x0 C., preferably of 15 to 40xc2x0 C., for a period of time ranging from 8 to 144 hours, preferably from 10 to 96 hours.
The product is obtained in the form of colourless crystals.
The reaction of the second stage is carried out with a molar ratio of the compound (III) to the compound (IVa) or (IVb) of between 0.95 and 2.1, according to the situation, at a temperature of 30 to 70xc2x0 C., preferably of 40 to 55xc2x0 C., for a period of time of 0.5 to 8 hours, preferably of 1 to 6 hours.
Furthermore, the second stage is generally carried out in the presence of at least one stabilizer chosen in particular from hydroquinone methyl ether, 3,5-di(tert-butyl)-4-hydroxytoluene and hydroquinone, and mixtures of these stabilizers, in a proportion of 100 to 2 000 ppm with respect to the charge.
Another subject-matter of the present invention is homopolymers or copolymers comprising units of at least one monomer of formula (Ia) or (Ib) as defined above.
The copolymers based on the monomers (Ia) and (Ib) can be water-soluble or hydrophobic polymers presented in the form of an aqueous dispersion, latex, aqueous solution, inverse emulsion or powder. They are prepared by radical copolymerization by various synthetic processes, such as dispersion, solution, direct emulsion, inverse emulsion, inverse suspension and water-in-water polymerization processes.
The present invention also relates to the compounds of formula (III) as defined above as intermediate compounds in the preparation of the compounds (I).